Wednesday, 15 June 2016

Go ahead, sketch a face on your note paper. Use a photo of someone as a guide if you want. Unless you're a trained artist, the chances are that you've made an elementary error, placing the eyes too far up the head, when it fact they should be halfway. Research suggests about 95 per cent of us non-artists tend to make this mistake and in a new study in the Psychology of Aesthetics, Creativity and the Arts, psychologists in America have attempted to find out why. The answer it turns out is rather complicated and concerns both our lack of knowledge and basic biases in the way that we pay attention to faces and to space in general.

Justin Ostrofsky and his colleagues asked 75 psychology undergrads to draw two faces shown on a computer screen – both were identical except one had hair and one was bald. Crucially, half the participants were told that the eyes on a human face typically appear halfway down the head, whereas the other participants weren't given this information.

Overall the participants made the usual error that people make when drawing faces and placed the eyes too far up the head, even though they had the model faces to guide them. But this error wasn't as extreme in the participants who were given the specific guidance about eye position. This tells us that at least part of the reason that non-artists place the eyes too high is because we don't know (or we've never noticed) their precise schematic location in a face.

However, the fact that the participants given this information still placed the eyes too high suggests that there is more to this than a lack of schematic knowledge. Another factor seems to be that when looking at faces, we tend to ignore the forehead region (this has been shown by prior research that's tracked people's gaze while they look at faces). Instead, we pay more attention to the parts of the face that contain features. The relevance of this to drawing was shown by the fact the participants made a smaller error with eye position when drawing the face that had hair than the face that was bald. The researchers explained: "When drawing the bald model, the absence of the hair line creates a larger forehead region to ignore and attenuate, resulting in the eyes drawn even further up the head in the bald model."

Yet another relevant factor seems to be our natural bias towards ignoring the upper end of vertical space. This is easy to demonstrate by asking people to mark the mid-point of a vertical line – most of us place the mid-point too high, which in neuropsychological jargon is a sign of "altitudinal neglect", meaning that we neglect to attend to higher space.

In the current study, the researchers asked their participants to perform a vertical line bisection and they found that the greater their altitudinal neglect (marking the line midpoint higher), the higher they tended to place the eyes on the faces they drew. But intriguingly this association was only true for the participants who were given the factual information about the eyes being midway down a human face. It seems being given this schematic knowledge improves our drawing, but only to a point – ultimately we're still led astray by a basic attentional bias (presumably artists learn to overcome this bias).